<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <textarea name="" id="" cols="30" rows="10"></textarea>
    <button>发布</button>
    <ul></ul>
     <script>
        var text =document.querySelector('textarea');
        var btn = document.querySelector('button');
        var ul = document.querySelector('ul');
        btn.onclick = function(){
            if(text.value == ''){
                alert('你还没有输入内容')
            }
            else{
                var li = document.createElement('li');
                 li.innerHTML = text.value+"<a href='javascript:;'>删除</a>";
              //javascript:;/javascriptvoid(0) --阻止链接跳转
                ul.insertBefore(li,ul.children[0]);
            }
             var as = document.querySelectorAll('a')
                for(var i =0;i<as.length;i++){
                    as[i].onclick = function(){
                        ul.removeChild(this.parentNode);
                      //删除的是li，当前a所在的li，this.parentNode
                    }
                }
        }
    </script>
</body>
</html>